Communications driver management

ABSTRACT

The creation of a virtual network adapter is disclosed. At least one existing network device having an existing driver is discovered. At least one of an existing device-to-driver mapping and an existing driver associated with the existing network device is removed. A new driver capable of communicating with the existing network device using a common set of primitive commands is installed. The new driver is mapped to the existing device. The use of the virtual network adapter is also disclosed.

CROSS REFERENCE TO OTHER APPLICATIONS

This application is a continuation of co-pending U.S. patent applicationSer. No. 13/480,058, entitled COMMUNICATIONS DRIVER MANAGEMENT filed May24, 2012 which is incorporated herein by reference for all purposes,which is a continuation of co-pending U.S. patent application Ser. No.13/470,048, entitled COMMUNICATIONS MANAGEMENT filed May 11, 2012 whichis incorporated herein by reference for all purposes.

BACKGROUND OF THE INVENTION

Individuals increasingly expect the presence of reliable access to theInternet, irrespective of where they are. Unfortunately, individuals canface a variety of challenges in obtaining such access. As one example,the quality of a given connection can vary based on where the individualis physically located. As another example, a particular link may becongested (e.g., due to heavy use by other individuals) resulting inlower available bandwidth.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the invention are disclosed in the followingdetailed description and the accompanying drawings.

FIG. 1 is a diagram illustrating an embodiment of an environment inwhich fractional encoding and decoding of packets is performed.

FIG. 2 illustrates an embodiment of a client device.

FIG. 3 illustrates an embodiment of a process for creating a virtualnetwork adapter.

FIG. 4 is a conceptual diagram that illustrates an example of a clientafter a communication aggregation application and a virtual networkadapter have been installed.

FIG. 5 illustrates an embodiment of a process for using a virtualnetwork adapter.

FIG. 6 illustrates an embodiment of a process for bringing up a link.

FIG. 7 illustrates components associated with a communicationaggregation application in some embodiments.

FIG. 8 illustrates an example of fractional threshold encoding accordingto one embodiment.

FIG. 9 illustrates an example of fractional threshold decoding accordingto one embodiment.

FIG. 10 illustrates an example of a process for creating fractionalpackets.

FIG. 11 illustrates an example of a process for reconstructingfractional packets.

FIG. 12 illustrates an example of a fractional split decision and linkperformance feedback loop.

FIG. 13 illustrates information used in determining a fractional split.

FIG. 14 illustrates an example of the first iteration of a process forperforming a fractional split decision.

FIG. 15 illustrates an example of the second iteration of a process forperforming a fractional split decision.

FIG. 16 illustrates an example of an additional iteration of a processfor performing a fractional split decision.

FIG. 17A illustrates an example of a fractional split decision made witha target loss of 1.0%.

FIG. 17B illustrates an example of a fractional split decision made withtarget loss of 0.0001%.

FIG. 18 illustrates an embodiment of an interface for managing aggregatecommunications.

DETAILED DESCRIPTION

The invention can be implemented in numerous ways, including as aprocess; an apparatus; a system; a composition of matter; a computerprogram product embodied on a computer readable storage medium; and/or aprocessor, such as a processor configured to execute instructions storedon and/or provided by a memory coupled to the processor. In thisspecification, these implementations, or any other form that theinvention may take, may be referred to as techniques. In general, theorder of the steps of disclosed processes may be altered within thescope of the invention. Unless stated otherwise, a component such as aprocessor or a memory described as being configured to perform a taskmay be implemented as a general component that is temporarily configuredto perform the task at a given time or a specific component that ismanufactured to perform the task. As used herein, the term ‘processor’refers to one or more devices, circuits, and/or processing coresconfigured to process data, such as computer program instructions.

A detailed description of one or more embodiments of the invention isprovided below along with accompanying figures that illustrate theprinciples of the invention. The invention is described in connectionwith such embodiments, but the invention is not limited to anyembodiment. The scope of the invention is limited only by the claims andthe invention encompasses numerous alternatives, modifications andequivalents. Numerous specific details are set forth in the followingdescription in order to provide a thorough understanding of theinvention. These details are provided for the purpose of example and theinvention may be practiced according to the claims without some or allof these specific details. For the purpose of clarity, technicalmaterial that is known in the technical fields related to the inventionhas not been described in detail so that the invention is notunnecessarily obscured.

FIG. 1 is a diagram illustrating an embodiment of an environment inwhich fractional encoding and decoding (also referred to herein as“reconstruction”) of packets is performed. In the example shown, client102 is a laptop computer belonging to an individual hereinafter referredto as “Alice.” Alice uses her laptop in a variety of locations,including at her home and at her office. Alice also uses her laptop inother locations, such as: (1) when commuting to and from her office on atrain that offers wireless Internet service to passengers; (2) in ahotel room that offers wired Internet connectivity; and (3) in a cafénear the hotel that offers wireless Internet service. As will bedescribed in more detail below, client 102 includes packetencoding/decoding tools. Client 102 also includes various modems,network adapters, and/or other networking hardware.

In addition to laptop 102, Alice has a tablet device 104 and asmartphone 106. Laptop 102 can be configured to share its networkconnectivity with additional devices, such as devices 104 and 106. Forexample, if Alice's laptop 102 has two wireless LAN cards, one can beused to provide connectivity to tablet 104 and the other used to connectto a wireless access point. If Alice has only one wireless LAN card,other networking components present in laptop 102 can be used to obtainnetwork connectivity (e.g., via Internet 116) and the sole wireless LANcard can be used to provide connectivity to tablet 104. As anotherexample, if Alice's laptop 102 includes a Bluetooth radio, the Bluetoothradio can be used to share whatever aggregate internet connectivitylaptop 102 has with smartphone 106 (which also includes a Bluetoothradio).

Aggregation Overview

Suppose Alice is currently riding on a train commuting to her office.She wishes to connect to server 122 using an application 402 thatsupports the SSH protocol. Server 122 has an Internet-routable address.Alice also wishes to browse website 120 using a browser application 404.One option for Alice is to use the wireless services provided by thetrain operator (represented as wireless access point 124 in FIG. 1) tomake connections to server 122 and website 120. Using the techniquesdescribed herein, Alice can also aggregate any additional connectivityshe might have (e.g., via a removable 3G USB modem) to improve herexperience, such as by increasing her bandwidth and/or by increasing thereliability of her connections with server 122 and website 120.

Now suppose that rather than being on a commuter train, Alice is at ahotel that offers DSL services through a wired connection in her hotelroom. Alice could use the wired services provided by the hotel toconnect to server 122 and website 120. Using the techniques describedherein, Alice can also aggregate any additional connectivity she mighthave, such as may be provided by the 3G USB modem, and/or such asthrough an open wireless access point 128 operated by a café that iswithin range of her hotel room.

Fractional Packet Overview

As will be described in more detail below, packets associated withapplications installed on client 102, such as applications 402 and 404,are transformed into fractional packets and transmitted across one ormore available links. Examples of such links are connections madebetween client 102 and infrastructure 110-114 provided by respectivewireless carriers. As one example, infrastructure 110 can be provided bya carrier such as Verizon Wireless (e.g., supporting 3GPP Long TermEvolution communications). Infrastructure 112 and 114 and any additionalinfrastructure can be provided by other carriers (e.g., Sprint NextelCorporation) and support other forms of communications (e.g., EDGE orWiMAX). A given infrastructure typically comprises multiple nodes inmultiple locations, but is depicted in FIG. 1 for conciseness as asingle tower. Other examples of links include connections made betweenclient 102 and wireless access points 124 and 128; between client 102and any wired infrastructure, such as a DSL router 126 located in ahotel; and between client 102 and a portable wireless hotspot (notshown).

The fractional packets are ultimately received by system 118 (which islocated, e.g., at a data center or a head end of a service provider),which reconstructs client 102′s packets from the fractional packets androutes the resulting reconstructed packets to their appropriatedestinations (e.g., network nodes 120 and 122). Any return trafficintended for client 102 (e.g., from nodes 120 and 122) is routed tosystem 118 which fractionally encodes the return traffic and causes itto be routed to client 102. On client 102, the fractional packets aredecoded and the recovered information is provided to the SSH and browserapplications, as applicable. While both client 102 and system 118 areboth capable of both encoding and decoding fractional packets, forconciseness, the examples described herein will generally reference theencoding of packets by client 102 and the decoding of packets by system118.

Client Device

FIG. 2 illustrates an embodiment of a client device. In the exampleshown, client device 102 is a commodity laptop computer comprisingtypical hardware elements and a variety of consumer-oriented wirelesscards. In particular, client 102 includes a CPU 202, RAM 204, andstorage 206 (such as one or more hard disks). Other components, such asa display and one or more input interfaces, can also be included, asapplicable. In the examples described herein, client 102 runs anoperating system provided by Microsoft Corporation, such as Windows 7.Clients running other operating systems can also be used and thetechniques described herein adapted as applicable.

Also included in client 102 are a variety of networking components208-214 that facilitate network communications. Such networkingcomponents can be fixed (e.g., integrated into client 102 at the time ofmanufacture or added as a hardware upgrade). Such networking componentscan also be removable (e.g., insertable by a user into a slot such as aUSB, PCMCIA, ExpressCard, MiniPCI, MiniPCI Express, and/or any otherappropriate peripheral interfaces). In various embodiments, any ofnetworking components 208-214 are omitted and/or additional networkingcomponents are included.

As shown, client 102 includes a commodity Ethernet component 208 and acommodity wireless LAN component 210. Client 102 also includes twooff-the-shelf consumer wireless cards 212-214. Removable 3G USB modem212 is sold by the carrier that provides infrastructure 110 (hereinafter“Carrier A”). Alice has a postpaid data plan with Carrier A which allowsher to use unlimited data (at up to 3G speeds) for $50 per month.Removable LTE USB modem 214 is sold by the carrier that providesinfrastructure 112 (hereinafter “Carrier B”). Alice has a prepaid planwith Carrier B whereby each Gigabyte of data costs her $15. When Alicehas access to wired Ethernet services (e.g., when she is at her officeor at a hotel), Ethernet component 208 can provide Alice with networkconnectivity (whether for free or for a fee). Similarly, when Alice isin range of a suitable access point, wireless LAN component 210 can alsoprovide Alice with network connectivity. As will be described in moredetail below, the network resources made available via networkingcomponents 208-214 (or other appropriate networking components) can beaggregated using a virtual network adapter. In some embodiments, theaggregated resources will appear to client 102 as a single layer twoconnection.

Creating a Virtual Network Adapter

FIG. 3 illustrates an embodiment of a process for creating a virtualnetwork adapter. In various embodiments, the process shown in FIG. 3 isperformed on client 102. Whenever client 102 is described as performinga task, a single component, a subset of components, or all components ofclient 102 may cooperate to perform the task. Similarly, whenever acomponent of client 102 is described as performing a task (e.g.,application 406), a subcomponent may perform the task and/or thecomponent may perform the task in conjunction with other components.

Process 300 begins at 302 when installer software is received. Theinstaller software can be received in a variety of ways. For example,the installer software can be bundled with a networking component, suchas by being included on removable USB modem 212. When Alice inserts theUSB modem the first time, she is prompted to install the installersoftware, which is received at 302 by client 102. As another example,Alice could download the installer software from a website using browserapplication 404.

When the installer software is executed, a client application is copiedto an appropriate location on client device 102 (e.g., a directory onstorage 206). The client application is also referred to herein ascommunication aggregation application 406. The installer software also,at 304, installs a generic USB modem driver. One example of such adriver is built as a lightweight wrapper around the “WinUSB” genericdriver provided by Microsoft Corporation. Associated with the genericUSB modem driver is a .INF file that maps particular devices to thegeneric USB modem driver (e.g., via a vendor ID and product IDassociated with the device). For example, identifiers corresponding to3G USB modem 212 and LTE USB modem 214 are both present in the .INF fileand map those modems with the generic USB driver.

In some cases, existing drivers for devices such as modems 212 and 214may already be present on client 102. For example, Alice may have beenusing the modems for some time prior to downloading the installersoftware. The generic USB modem driver installed at 304 has propertieswhich in some cases give it priority over the previously installeddrivers by the operating system. For example, the .INF file may containa “Feature Score” directive which increases the priority of the driveras computed by Microsoft Windows. However, in some cases, additionalprocessing (306-308) may be needed to successfully map USB networkdevices 212-214 with the generic USB driver. One approach is to removeany existing USB device-to-driver mappings (306). In this approach theexisting driver is not removed—just the mapping (e.g., the entry in the.INF file). A second approach is to remove any conflicting drivers (308)from client 102. In various embodiments, Alice's permission is requestedby the installer software prior to actions 306 and/or 308 being taken.As one example, Alice can be informed that an existing driver is aboutto be uninstalled, and asked whether she would like to save a backupcopy of the driver prior to its removal.

Based on the USB specification, a given device may be composed ofmultiple interfaces which are in turn composed of multiple endpoints.Some operating systems will treat such a device as a single device.Other operating systems operate at the interface level, meaning thatwhen such a device is plugged in, each of the multiple interfaces willappear to be a separate device (sometimes referred to as a “compositedevice”). In some embodiments, the installer software is configured toprevent a multiple-interface device from being treated by the operatingsystem as multiple devices—instead installing a driver for the basedevice, only.

Finally, at 310, the virtual network adapter is installed.

FIG. 4 is a conceptual diagram that illustrates an example of client 102after a communication aggregation application and a virtual networkadapter have been installed. Dotted line 410 represents a conceptualdivision between kernel space (above the line) and user space (below theline). As shown, network components 214 and 212 are handled by operatingsystem 414 using the wrapped WinUSB generic driver 412. Operating system414 exposes a WinUSB endpoint 416 that applications such ascommunication aggregation application 406 can bind to. Ethernetcomponent 208 and wireless LAN component 210 have their own respectivedrivers (418 and 420) and are also exposed by operating system 414 foruse by applications (via respective adapters 422 and 424).

Using the Virtual Network Adapter

FIG. 5 illustrates an embodiment of a process for using a virtualnetwork adapter. In various embodiments, the process shown in FIG. 5 isperformed on client 102. The process begins at 502 when communicationaggregation application 406 is started. Application 406 can be startedin a variety of ways. As one example, application 406 can automaticallystart whenever client device 102 is turned on. As another example,application 406 can automatically start whenever a removable networkingcomponent (e.g., modem 212) is inserted into client 102. As yet anotherexample, application 406 can be started on demand by Alice.

At 504, any networking devices present in client 102 are enumerated. Insome embodiments, enumeration is performed by enumerator 712. One way toperform enumeration is to examine the .INF file for the presence onclient 102 of any devices included in the file. Ethernet and WirelessLAN devices that are not included in the .INF file but are present inclient 102 (e.g., 422 and 424) are also enumerated. One way to performthis enumeration is to scan for the presence of network adapterinterfaces (422 and 424) corresponding to devices 208 and 210. Anotherway to perform enumeration is to consult a device database 702 thatincludes information on devices previously used by client 102 (which caninclude both fixed and removable devices). In some embodiments, portion504 of process 500 is repeated periodically (e.g., every 60 seconds).

At 506, a request is made to register for asynchronous notifications. Insome embodiments, the request is made by link manager 732. If anyadditional networking devices are inserted (and/or turned on), or if anynetworking devices are removed (and/or turned off), application 406 willbe notified accordingly through asynchronous notifications. Suchnotifications are managed by notification handler 714. In someembodiments, a filter is applied by the notification handler to receivednotifications so that only changes in status/additions/removals ofnetworking devices of interest (and not, e.g., devices not of interest,such as USB mice) are monitored for. In some embodiments, portion 504 ofprocess 500 is repeated whenever an asynchronous notification involvinga network device of interest is received. In some embodiments, portion506 of the process is omitted. For example, users can be asked to insertall removable devices prior to starting application 406, or can be askedto insert all removable devices after starting application 406. Periodicre-enumeration can also be employed, without using the processingperformed at 506.

At 508, the virtual network adapter is opened. Finally, at 510, linkssuch as a connection between client 102 and infrastructure 110 and/or aconnection between client 102 and infrastructure 112 are opened.Applications 402 and 404 use virtual network adapter 408 for theirnetwork communications. Packets received from those applications via thevirtual network adapter are processed by communication aggregationapplication 406 which in turn causes fractional packets to be sent outover the link(s).

Additional detail regarding portions of process 500 and regardingcomponents of communication aggregation application 406 is provided inconjunction with FIG. 6, FIG. 7, and the accompanying descriptions ofthose figures.

FIG. 6 illustrates an embodiment of a process for bringing up a link. Insome embodiments, process 600 is performed at 510 in process 500 foreach enumerated networking device. In the following discussion of FIG.6, removable 3G USB modem 212 is used as an example of an enumeratednetworking device for which a link is brought up.

The process begins at 602 when a Dispatcher is run, in parallel, on eachinterface of an enumerated networking device. Each Dispatcher isconfigured to run applicable scripts included in script database 740.Dispatchers perform tasks such as initializing its associated networkingdevice. As will be discussed in more detail below, modem 212 includesmultiple interfaces and multiple Dispatchers will be brought up for thedevice in parallel accordingly. Certain commands (such as “power onradio” or “fetch signal strength”) are applicable to all devices.However, each device may have a specific, distinct way of beinginstructed to execute the command. By using a combination of Dispatchersand device-specific scripts, commands can be issued to devices using acommon set of primitives (e.g., a generic “power on radio” instruction)that are then implemented by the implicated Dispatcher/script. Changescan be made to the scripts without requiring a reboot of client 102.

At 604, applicable initialization (INIT) commands are sent. One exampleis a USB command to turn on a modem. Another example is an AT command toset a variable.

At 606, applicable information is fetched (e.g., from device database orscript database 740). Examples of such information include phone numbersand/or settings information.

At 608, the primary interface is instructed to perform a dialingoperation. The particular manner in which dialing should be performed ona given device can be specified using device database 702 and scriptdatabase 740 and any applicable settings (e.g., configuration 734).Typically, irrespective of how many interfaces a device has, only oneinterface will enter data mode. In some embodiments, that interface ishooked to PPP stack 750.

Finally, as applicable, at 610, a status fetching loop is entered intoon a secondary interface. Some networking components have severalinterfaces. For example, link 716 includes three interfaces (720-724).One interface (e.g., interface 720) is used for dialing. The secondinterface (e.g., interface 722) is used for initialization. The thirdinterface (e.g., interface 724) is used to monitor signal strength.Other networking components have fewer interfaces. For example, link 718has only two interfaces (726-728). The first link (726) will be used tosend and receive data, leaving the second link (728) the only oneavailable to perform tasks such as checking signal strength or changingsettings. The status fetching loop (610) can be employed to use thesecondary interface to perform multiple types of tasks. As one example,the Dispatcher associated with the secondary interface can loop througheach of the status-related tasks (e.g., determining signal strength,then determining latency). In some embodiments, a background queue isemployed so that user-initiated requests (e.g., changes to settings) canbe interleaved with the status fetching operations. One way for theDispatcher to make use of a background queue is for the Dispatcher toyield every five seconds for five seconds to process any items waitingin the background queue.

Some devices provide “unsolicited messages.” For example, 3G USB modem212 may generate a message that it has switched towers, whenever itswitches towers. In various embodiments, link manager 732 is configuredto monitor for the presence of such unsolicited messages, and place themin a queue for processing, if applicable. For example, if a tower switchmessage is received from a link, the current tower information (738) isupdated accordingly. Other messages may not be of interest to linkmanager 732 and are dropped or otherwise ignored instead of being addedto the queue. Instructions for which unsolicited messages should beprocessed and which should be ignored can be stored in a variety ofplaces, including as device configuration information 734, in scriptdatabase 740, or any other appropriate location.

FIG. 7 illustrates components associated with communication aggregationapplication 406 in some embodiments. The components depicted in Figured7 can be included within the application and can also be located outsidethe application but be usable by or work in cooperation with theapplication as applicable. Whenever application 406 performs a task(such as receiving encoding or decoding a packet), either a singlecomponent or a subset of components or all components of application 406may cooperate to perform the task.

Link manager 732 manages the enumerated links (e.g., links 716 through718) and is responsible for tracking information such as the currentstate of each of the links, configuration information (734), metadata(736), which tower the link is connected with (738) if applicable, etc.Enumerator 712 performs enumeration and re-enumeration of devices(described in more detail in conjunction with portion 504 of process500). Asynchronous notification handler 714 listens for notificationsfrom operating system 414 (described in more detail in conjunction withportion 506 of process 500).

One example of a link is link 716. As previously explained, link 716includes three interfaces 720-724, each of which has an associatedDispatcher (742-746). In the example shown, suppose link 716 correspondsto 3G USB modem 212. When enumerator 712 enumerates modem 212, linkmanager 732 determines which configuration information (e.g., 734) andscripts are applicable to the device by consulting device database 702.Link manager 732 then instructs Dispatchers 742-746 to obtain theappropriate scripts (e.g., script 752) from script database 740. As oneexample, script 752 could be responsible for looping and fetching signalstrength for device 212.

Also included in application 406 is aggregation core 710. When a link isbrought up (e.g., link 716), a corresponding endpoint (e.g., endpoint748) is created. When packets are received via virtual network adapter408, packet service 706 provides the stream of packets to theaggregation core 710, which performs fractional encoding (and decoding)and sends the fractional packets over the various endpoints.

As described in more detail below, for each input packet (received bythe packet service from client 102), two parameters n and m areselected, which together define the granularity and redundancy of thefractional encoding. Specifically, for an input packet of size k, anencoder in the aggregation core generates m fractional packets of sizek/n such that having any n of the m pieces allows the original packet tobe reconstructed. The fractional packets are then sent over theavailable links to system 118, which is able to rebuild the originalpacket as soon as it receives the “threshold” number of packets n. Inthe case where one fractional packet is sent on each available link, theeffective bandwidth of the system is n times the bandwidth of the n^(th)fastest link, with significant redundancy added via the m-n extrapackets.

Various techniques can be used to create fractional packets from theinput packets. In the examples describe herein, the technique used togenerate fractional packets is based on Shamir's secret sharing method.However, other cryptographic secret sharing techniques may also be used,as may other techniques, such as Reed-Solomon erasure codes with forwarderror correction, turbo codes, parity-check codes, convolutional codes,Hamming codes, etc., and the techniques described herein adapted asappropriate.

Additional sources of information can also be used in determining n andm and in the assignment of the resulting fractional packets to links. Asone example, link performance data includes information such as theestimated capacity of each link or the loss rate of each link. Onesource of link performance data includes information provided by thedevice providing the respective link. For example, link 716 has theability to report on its signal quality, an example of performance data730. In some cases, such as a satellite link, link performance may besignificantly better in one direction than the other. Application 406can specify that a satellite link be used only for downlink, while otherlinks are used for uplink, or that only a portion (e.g., 25% of traffic)be sent via the satellite connection.

Quality of Service requirements 704 are specified by a user such asAlice and allow Alice to specify desired link quality targets such asloss rate or latency. For example, if all links are lossy, or if a lowpacket loss rate is desired, application 406 may determine to reduce n,which makes it more likely that enough data will be received toreconstruct the packet. In various embodiments, Alice is able toconfigure other goals as well. For example, if client 102 is being usedto facilitate a VOIP call, it might be preferable to reduce latency,even at the cost of a higher loss rate. Conversely, if client 102 ismaking use of TCP, a more stable connection might be preferable. Asanother example, Alice can specify that she prefers to favor the use ofa link associated with a monthly flat rate fee over a pay-by-use link.As another example, if Alice is about to make a critical high definitionvideo call, she may prefer to optimize her aggregate connection forbandwidth and/or reliability, even if it means paying more for theconnection.

An example of an interface displaying status to Alice is shown in FIG.18. As described in more detail below, the link performance data and QOSrequirements can change dynamically over time, and other inputs toapplication 406 can also be used (or omitted) as applicable.

Fractional Encoding

FIG. 8 illustrates an example of fractional threshold encoding accordingto one embodiment. In the example shown, the (3,4) case (i.e., n=3, m=4)is used and Galois Field 2⁸ is used as the computation space. Otherfractional splits and fields can also be used, as applicable. Links802-808 represent the links available to application 406.

The process begins with an input packet (810) of size k, whose bytes areb₁, b₂, . . . , b_(k). If k is not a multiple of 3, the buffer is paddedwith zeroes so that it is. For each consecutive triplet of three bytes(e.g., v₁, v₂, and v₃), a degree 2 polynomial P_(i) is constructed wherethe bytes are the coefficients of the polynomial P_(i)(x)=v₁x²+v₂x+v₃.Since there are three bytes per polynomial, there are k/3 of thesepolynomials.

Next, each of the output fractional packets 812-818 is built as follows.For each output fractional packet, a unique sample point (e.g., 0-255)is chosen. In the example shown, zero is used first, and the number isincremented by one for each output packet. The first three bytes of thefractional packet are set to the packet ID, sample point, and the numberof packets needed for reconstruction. This data allows system 118 tomatch up incoming fractional packets and determine when sufficient datahas been received to attempt decoding.

The rest of the bytes in the fractional packet come from evaluating eachof the k/3 polynomials at the selected sample point. In the exampleshown, this results in four output packets each having length

$\left( {\frac{k}{3} + 3} \right)$

bytes.

FIG. 9 illustrates an example of fractional threshold decoding accordingto one embodiment.

In the example shown, assume that the fractional packet sent over link806 has been lost. Accordingly, only three of the four packets sent inthe process shown in FIG. 5 are available for reconstruction. As eachfractional packet arrives, it is stored in a buffer based on the packetID. Once three packets corresponding to the same packet ID have beencollected, it is known based on the fractional packet headers that asufficient number of pieces have been received by system 118 to begindecoding.

The process begins by first constructing the unique Lagrangeinterpolation polynomials for the sample points that are used in thereconstruction. In the example shown in FIG. 9, sample points zero, one,and three are present.

As per the Lagrange interpolation process, system 118 can then directlymultiply these basis polynomials with the sample points and add theresults together to obtain the coefficients of the original polynomialsP_(i), which correspond to the bytes in the original packet. The decoderthen directly rebuilds the original packet by putting the coefficientsinto a buffer.

FIG. 10 illustrates an example of a process for creating fractionalpackets. In some embodiments the process shown in FIG. 10 is performedby application 406. The process begins at 1002 when a packet isreceived. For example, at 1002 a packet is received from application 404by packet service 706. At 1004, one or more fractional packets areconstructed from the received packet. For example, at 1004, theprocessing shown in FIG. 8 is performed. At 1006, the fractional packetsare transmitted. For example, at 1006, one fractional packet istransmitted via each of the available links 802-808.

FIG. 11 illustrates an example of a process for reconstructingfractional packets. In some embodiments the process shown in FIG. 11 isperformed by system 118. The process begins at 1102 when fractionalpackets are received. For example, at 1102 a fractional packet isreceived from link 802 and another is received from link 804. Once asufficient number of fractional packets have been received, at 1104, theoriginal packet is reconstructed. For example, once a fractional packetis received from link 808, per the example shown in FIG. 9, the originalpacket can be reconstructed at 1104. At 1106, the original packet istransmitted. For example, if the packet is intended for website 120, at1106 the packet is transmitted to website 120.

FIG. 12 illustrates an example of a fractional split decision and linkperformance feedback loop. Using the techniques described herein,application 406 is able to respond in real-time to changes in thecapacities of the links. In some embodiments application 406 decides howto split packets based on stateful and stateless information that itmaintains for each link. One example of such a decision process is onethat stores estimated link capacities C₁, C₂, . . . , C_(j) for each ofthe j links. This stateful data is combined with stateless inputs suchas a target loss factor used by a fractional split decision (FSD)algorithm which determines the number and size of the pieces to be senton each link.

At any one time, the fractional encoder maintains a best estimate oflink capacities C₁, C₂, . . . C_(j) corresponding to the j links. Asfractional packets are sent from application 406 to system 118, thereceiver (system 118) is responsible for examining the packets as theyarrive for information to aid in refining the capacity estimates. Thiscan be done using a variety of techniques such as inter-packet arrivaltiming by identifying packet trains, or simple time averaging of dataarrival, etc.

The end result of the receiver-side analysis is link capacity updateinformation for each link U₁, U₂, . . . , U_(j) as shown at 1202. Thisinformation is sent from system 118 back to application 406, which thenapplies this information to update the estimated link capacities.

FIG. 13 illustrates information used in determining a fractional split.The information shown illustrates a sample case in which an input packetof size 1000 is to be split over four links whose estimated capacities(e.g., as determined by the process described in conjunction with FIG.7) are 2.0, 1.0, 0.5 and 0.5 Mbits/sec respectively, as shown in region1302.

The process begins by normalizing the link capacities with respect tothe fastest link. In this case, the relative capacities are 1.0, 0.5,0.25, and 0.25, as shown in region 1304.

In the example shown, a static estimated loss rate and loss target isused. Accordingly, an allowed splits table of (n,m) fractional splits isbuilt that satisfies the loss criteria. Specifically, for each integervalue of m pieces to send out, the value n<=m is determined such thatthe probability of having at least n/m packets arrive is greater thanthe target threshold. This value may be computed based on the cumulativebinomial distribution.

In the example shown, an estimated loss rate of 0.001 per packet hasbeen selected, which indicates that 1 out of every 1000 packets will bedropped. The loss target is 0.00001, indicating that it is desired thateffectively only 1 out of every 100000 packets lose enough data so as toprevent reassembly. The first few values of the allowed splits table areshown in region 1306. The first pair (1,2) indicates that if two piecesare sent, each of them must be the full data (i.e., divided by 1) tosatisfy the loss target. The second pair (2,3) indicates that if threepieces are sent, each of the pieces could be half the size (i.e.,divided by 2) and the loss requirement would be met.

In some embodiments performing a fractional split decision includes theuse of a greedy solver that incrementally adds more pieces until itfinds the minimum global constraint among all the links. The processbegins by assigning zero packets to every link, and then computes foreach possible way to add one additional packet, the effectivedimensionless time it would take for all the data to reach the otherend.

FIG. 14 illustrates an example of the first iteration of a process forperforming a fractional split decision. In the example shown, beginningwith an initial solution of zero packets on each link, each possibleallocation of one additional packet is explored. Note that based on theselected loss criteria in this example, there is no way to satisfy theloss requirements if a single piece is sent. For purposes ofillustration, however, assume that the single piece is not split at all(i.e., the fraction is 1).

In the first case (1402), allocating the packet to the first link willresult in 1 piece of 1000 bytes sent on the first link and zero on therest. Since the first link has relative speed 1.0, this will take 1.0relative units of time to transfer. This is computed as (bytes tosend/original bytes)*(1/link capacity). For the other links, the 0 bytessent will take 0.0 units of time to transfer, and thus the overall timerequired for this allocation is the maximum time required on each link,which is 1.0.

In the second case (1404), allocating the packet to the second linkresults in there being 1 piece of 1000 bytes sent on the second link andzero on the rest. With a relative speed of 0.5, it will take the secondlink 2.0 relative units of time to transfer the pieces. As in the firstcase, the other links will require 0.0 units of time to transfer 0bytes. Thus the time required for this allocation is 2.0.

The third (1406) and fourth (1408) cases are similar, but with arelative speed of 0.25, each case results in a required time of 4.0.Therefore, the best greedy allocation choice is to allocate the packetto the first link so that the smallest effective time required totransfer the data is used. This solution is denoted as (1,0,0,0)−1.0.

FIG. 15 illustrates an example of the second iteration of a process forperforming a fractional split decision. The example shown repeats theprocessing described in conjunction with FIG. 9. In this example, thecurrent solution is (1,0,0,0) and the table of allowed splits indicatesthat for two pieces, each of them must be full size to meet the lossrequirements. An exploration of the four possible allocations for thenext piece is performed. They are denoted as configurations (2,0,0,0),(1,1,0,0), (1,0,1,0), and (1,0,0,1).

In the first case (1502), two packets of size 1000 are assigned to thefirst link, so the effective time required to send the 2000 bytes overthe 1.0 capacity link is 2.0. In the second case (1504), one packet ofsize 1000 is sent on the first link and one packet of size 1000 is senton the second link. The first link's effective time is 1.0 and thesecond link's effective time is 2.0, so the effective time to transferis 2.0.

Similarly, for the third (1506) and fourth (1508) cases, the effectivetime is 4.0. The best solution using two pieces is therefore (2,0,0,0),yielding an effective time of 2.0. While this is larger than theeffective time of the previous solution (1,0,0,0), the previous solution(using a single piece) does not meet the loss criteria and so the newsolution, denoted (2,0,0,0)−2.0 is stored as the new overall bestsolution.

FIG. 16 illustrates an example of an additional iteration of a processfor performing a fractional split decision. As in previous iterations,the process begins with the solution of the previous iteration (2,0,0,0)and examines the solutions with one additional packet—(3,0,0,0),(2,1,0,0), (2,0,1,0), and (2,0,0,1). The allowed split factors tableindicates that for three pieces, each of the pieces can be half the size(divided by factor of 2). Therefore, each piece now has a size of 500bytes instead of the full 1000.

In the first case (1602), 3×500 byte pieces are sent on the first link,for a total of 1500 bytes being sent over a 1.0 capacity link. Thisresults in an effective time of 1.5. In the second case (1604), 2×500byte pieces are sent on the first link of capacity 1.0, and 1×500 bytepacket is sent on the second link of capacity 0.5. Thus, the requiredtime for the first and second links is 1.0.

In the third (1606) and fourth (1608) cases, the required time is 2.0.Thus, the best greedy solution with three pieces is (1,1,0,0), whichresults in an effective time of 1.0. Since this time is less than theprevious best overall solution of (2,0,0,0)−2.0, the new solution issaved as the overall best one.

Iteration may proceed up to an arbitrary number of pieces, and the endresult is designated as the global optimal split decision thatdetermines the split factor and number of pieces to create as well asthe number of pieces to send on each link.

FIG. 17A illustrates an example of a fractional split decision made witha target loss of 1.0%. FIG. 17B illustrates an example of a fractionalsplit decision made with target loss of 0.0001%. FIGS. 17A and 17Billustrate how QOS parameters may affect a fractional split decision. InFIGS. 17A and 17B, respectively, the links have normalized speeds of 1.0and 0.5. In both cases, the estimated probability of loss of a singlepacket is 0.1% or 0.001. The difference between the two cases is thatthe first uses a target loss probability of 0.01 or 1% while the seconduses a target loss probability of 0.0001%.

As illustrated in FIGS. 17A and 17B, respectively, the example greedysplit decision is carried out as previously described. For compactness,only the first six iterations of the greedy algorithm are shown. Notethat the differing value for target loss in each case affects theallowed splits, which in turn affects the maximum possible split factorused at each iteration of the algorithm.

Applying the fractional split decision algorithm with a target loss of1% results in an encoder being able to split input packets as finely asthe number of packets it chooses to create, as indicated by the allowedsplits table. For example, the (5,5) entry in FIG. 17A indicates that ifthe encoder sends five pieces, each can carry a fifth of the inputpacket's data and still satisfy the loss requirement. On the other hand,the (5,3) entry in FIG. 17B indicates that if five pieces are sent, eachmust carry a third of the input packet's data in order to satisfy thetarget loss of 0.0001% used in FIG. 17B.

FIG. 17A shows that with a target loss of 1%, the optimal split is(2,1), with each of the pieces carrying a third of the original data.This results in each packet taking ⅔ of the time to be sent, increasingtotal capacity by 50%. On the other hand, FIG. 17B shows that with atarget loss of 0.0001%, the optimal split is (4,2), which results ineach packet taking the same time to be sent as the original inputpacket, but meets the much stricter loss requirements.

FIG. 18 illustrates an embodiment of an interface for managing aggregatecommunications. In various embodiments, interface 1800 is presented toAlice when she launches application 406, accesses a status webpage,clicks on an icon in her toolbar, loads an application on tablet 104 orsmartphone 106, etc. The interface is both touch-interface andmouse/keyboard friendly for a consistent cross-device experience.

Alice can enable or disable connection aggregation by toggling button1802.

If Alice clicks on tab 1804, she will be presented with a dashboard inher default browser. The dashboard displays information such as Alice'smonthly usage/charges with respect to any carriers associated with hernetworking devices. The dashboard also displays historical usageinformation, projections on when Alice will meet any set thresholds(e.g., 5 GB of usage on a particular link), etc. In various embodiments,Alice can configure application 406 remotely, via the dashboard, and/orcan configure links.

If Alice clicks on tab 1806, she will be presented with a settings menu,where she can set various preferences, such as to prefer low latency,prefer low cost, use a particular device only until a certain dollaramount or other usage is reached, then stop using it, etc.

Region 1808 is a real-time display of the upload and download throughputresulting from Alice's internet usage.

Region 1810 reports a metric that summarizes the quality of theaggregated connection and is updated in real time.

Region 1812 lists each of the individual links available foraggregation. Alice can elect to use all, or a subset of the availablelinks. One example link is shown in region 1814.

Alice can turn a given link on or off (i.e., indicating whether itshould be used for aggregation) by toggling button 1816.

Metadata associated with a given link is shown in region 1818. Examplesof such information include (if applicable): Link type, link provider,link phone number, link name, link encryption, link channel, linkconnection status, link model, link unique identifier, and link billingcycle dates.

A real time display of the signal quality of a given link, in dBm, isshown in region 1820. In the example shown, signal quality is alsosegmented into five discrete display bars.

A session usage meter is depicted in region 1822. The meter displays, inreal time, how much bandwidth has been used in one session (time betweenconnecting and disconnecting via application 406). The displaydynamically changes based on uplink type and usage limits.

In region 1824, a metric that summarizes the quality of the given linkis displayed. The metric is updated in real time.

In region 1826, a real time display of a given link's download andupload throughput is provided.

In region 1828, a real time display of a given link's measured latencyis provided.

If Alice clicks on control button 1830, a settings menu will openallowing her to configure settings specific to the applicable link. Asone example, Alice can specify usage restrictions for the link via thesettings menu.

As illustrated in region 1832, the information displayed for a givenlink can be different based on the type of link. The link in region 1832corresponds to a wireless network, whereas the link in region 1814corresponds to a USB modem.

Although the foregoing embodiments have been described in some detailfor purposes of clarity of understanding, the invention is not limitedto the details provided. There are many alternative ways of implementingthe invention. The disclosed embodiments are illustrative and notrestrictive.

What is claimed is:
 1. A system, comprising: a processor configured to:determine a presence of an existing driver associated with an existingnetwork device; remove at least one of: a mapping of the existingnetwork device to the associated existing driver; and the existingdriver associated with the existing network device; install a new drivercapable of communicating with the existing network device using a commonset of primitives, wherein commands are issued to the existing networkdevice at least in part by using the common set of primitives; and mapthe new driver to the existing network device; and a memory coupled tothe processor and configured to provide the processor with instructions.2. The system of claim 1 wherein the new driver is capable ofcommunicating with a plurality of existing network devices.
 3. Thesystem of claim 1 wherein the processor is further configured toaggregate resources provided by a plurality of network devices includingthe existing network device.
 4. The system of claim 1 wherein theexisting network device is a USB device and wherein the set ofprimitives includes USB commands.
 5. The system of claim 1 wherein theprocessor is further configured to perform the removing after receivingpermission from a user.
 6. The system of claim 1 wherein the existingnetwork device is a composite USB device having multiple interfaces andwherein installing the new driver includes installing a driver for thebase device and not installing additional drivers for additionalinterfaces of the composite USB device.
 7. The system of claim 1 whereinthe existing network device is a modem device.
 8. The system of claim 1wherein the existing network device is a mobile access point.
 9. Thesystem of claim 1 wherein the common set of primitives includes a set ofgeneric instructions.
 10. The system of claim 1 wherein commands areissued at least in part by using the common set of primitives that areimplemented at least in part by a script specific to the existingnetwork device.
 11. A method, comprising: determining a presence of anexisting driver associated with an existing network device; removing atleast one of: a mapping of the existing network device to the associatedexisting driver; and the existing driver associated with the existingnetwork device; installing a new driver capable of communicating withthe existing network device using a common set of primitives, whereincommands are issued to the existing network device at least in part byusing the common set of primitives; and mapping the new driver to theexisting network device.
 12. The method of claim 11 wherein the newdriver is capable of communicating with a plurality of existing networkdevices.
 13. The method of claim 11 further comprising aggregatingresources provided by a plurality of network devices including theexisting network device.
 14. The method of claim 11 wherein the existingnetwork device is a USB device and wherein the set of primitivesincludes USB commands.
 15. The method of claim 11 further comprisingperforming the removing after receiving permission from a user.
 16. Themethod of claim 11 wherein the existing network device is a compositeUSB device having multiple interfaces and wherein installing the newdriver includes installing a driver for the base device and notinstalling additional drivers for additional interfaces of the compositeUSB device.
 17. The method of claim 11 wherein the existing networkdevice is a modem device.
 18. The method of claim 11 wherein theexisting network device is a mobile access point.
 19. The method ofclaim 11 wherein the common set of primitives includes a set of genericinstructions.
 20. The method of claim 11 wherein commands are issued atleast in part by using the common set of primitives that are implementedat least in part by a script specific to the existing network device.